Shaped structures made of acrylonitrile polymers with antistatic additives

ABSTRACT

The invention relates to shaped articles, especially filaments, fibres and foils of acrylonitrile polymers containing as antistatic additives polyether polyurethanes of the general formula R-NHCO-(OCH2CH2)n-A-(CH2CH2O)n-(COHN-R&#39;&#39;-NHCO-(OCH2-CH2)n-A(CH2CH2O)n)p-OCNH -R

United States Patent [1 1 Wolf et a].

{54] SHAPED STRUCTURES MADE OF ACRYLONITRILE POLYMERS WITH ANTISTATIC ADDITIVES [75] Inventors: Gerhard Dieter Wclf, Dormagen; Francis Bentz, Cologne; Gunther Nischk, Dormagen, all of Germany [73} Assignee: Bayer Aktiengesellschaft,

Lcverkusen-Bayerwerk, Germany [22] Filed: Oct. 18, 1974 [Zl] App]. No; 516,132

[30] Foreign Application Priority Data Oct. 24. I973 Germany 23532l3 [52] U.S. CI.. 260/859 R; 260/7705 CR; 260/8505 S;

260/88] B [5]] Int. Cl. C08G 41/04 [58] Field of Search l. 260/859 [56] References Cited UNITED STATES PATENTS 3.038376 6/1962 Farago 0 260/85) R Oct. 7, 1975 3.380953 4/l968 Fukushima .0 260/859 R FOREIGN PATENTS OR APPLlCATlONS 9430 [2/ l 955 Germany 45277] l/I970 Japan 260/859 452772 1/1970 Japan 260/859 46-0659 1/1971 Japan 0. 260/859 Primary Examl'm'rPaul Lieberman Attorney Agenl, or Firm Plumley 8-: Tyner [57] ABSTRACT 4 Claims, N0 Drawings SHAPED STRUCTURES MADE OF ACRYLONITRILE POLYMERS WITH ANTISTATIC ADDITIVES This invention relates to shaped structures, e.g. filaments, fibres and foils, of acrylonitrile polymers which have been rendered permanently antistatic by the addition of certain polyether polyurethane compounds.

Shaped structures made of synthetic polymers, e.g. polyacrylonitrile fibres, generally have the disadvantage of becoming electrically charged, which limits their range of application. This unwanted build-up of electric charge occurs when the surface resistance of the fibres is more than 0.

Attempts have been made to reduce the electrostatic charge, for example by means of a surface treatment of the fibres, or of the textile products produced from them, with antistatic dressings which increase the electrical conductivity. The thus-obtained antistatic effect, however, is only slight, and, in most cases, it is not resistant to washing.

According to other known processes, an antistatic finish may be obtained by applying aqueous solutions of suitable substance to the fibres while they are in the aquagel state (see German Offenlegungsschrift Nos. 1,469,9l3 and [965,63 l In these processes, however, considerable difficulties arise in maintaining the particular operating conditions.

It is also known to mix polyacrylonitrile, for example with a second acrylonitrile polymer which contains from to 80 by weight, of a polyethylene oxide methacrylate and then to spin this mixture (see German Offenlegungsschrift No. 1,645,532). In general, however, the processes which involve increasing the electrical conductivity by copolymerising suitable comonomers have the disadvantage that they often substantially alter the desirable properties of the particular polymers.

In other processes frequently employed for reducing the static charge of shaped structures of synthetic polymers, polycthers or other suitable compounds are added to the solutions or solvent-free melts of these polymers before they are shaped. It is very difficult, however, to find compounds of this kind which will, on the one hand, be wash-resistant, i. e. which will not be removed from fibres of such polymers even by repeated washing with alkaline detergents, and which will, on the other hand, be compatible with the polymers. If a portion of the additives is removed by washing, socalled vacuoles" are formed and the fibres lose their glossy appearance and become mat owing to this Soil- Hiding-Effect".

Polyethers, and many compounds which contain polyether linkages, have the additional disadvantage of reducing the light-fastness of polymers to which they are added.

It has now surprisingly been found that the use of compounds which contain both polyether linkages and urethane groups impart wash-resistant, i. e. permanent antistatic properties, to polyacrylonitrile fibres without reducing the light-fastness of these polymers. This is all the more surprising in view of the known fact that urethane groups which are adjacent to a polyether linkage are susceptible to hydrolysis.

The urethane group containing polycthers of the present invention exhibit several advantages: in addition to their excellent compatibility with the polymers,

these additives impart excellent pennanent antistatic characteristics to polyacrylonitrile fibres. Vacuoles, which are normally caused by additives, are not produced by these urethane group containing polyethers and, lastly, no yellowing of the fibres is observed.

The present invention therefore relates to shaped structures of acrylonitrile polymers containing as antistatic additives from 0.5 to 15 by weight, based on the total mixture, of at least one polyether polyurethane compound of the general formula in which A denotes a bivalent radical of an aromatic biphenol of the formula in which R denotes a bivalent aromatic radical consisting of one or more condensed aromatic rings or of aromatic rings which are jointed together by a single bond or by a bridge member selected from the group consisting of O, S, SO CH CHCH:,, -C(CH;,) and it denotes a bivalent fivc-, sixor seven-membered heterocyclic radical which contains at least two nitrogen atoms and which is linked in the polyether chain by two nitrogen atoms;

R denotes a C C, alkyl, cycloalkyl, aralkyl, or alkaryl radical, and of which radicals may be substituted by halogen or alkyl;

R' denotes an alkylene, cycloalkylene, arylene,

aralkylene or alkarylene radical, any of which radicals may be substituted by halogen or alkyl;

n denotes an integer of from 5 to 50; and

p denotes O or an integer of from I to ID.

The shaped structures according to the present invention may be obtained by adding from 0.5 to l5 by weight, based on the polymer mixture, of one or more polyether polyurethane compounds corresponding to the above general formula to solutions of the acrylonitrile polymers. The solvent is then removed in a process which is accompanied by shaping.

The term shaped structures" includes threads, fibres and foils.

The polyether polyurethane compounds are preferably added in a quantity of from 2 to ID by weight, based on the polymer mixture.

The compounds included in the group of acrylonitrile polymers are, particularly, polyacrylonitrile or copolymers of acrylonitrile with (meth)-acrylic acid esters, e.g. methyl and ethyl esters of acrylic and methacrylic acid; with (meth)-acrylamides, e.g. (meth)-acrylamide and N,N-dimethyl-(meth)-acrylamide; with N-vinyl lactams, e.g. N-vinyl pyrrolidone; with vinyl esters or ethers and (meth)-allyl esters or ethers; with vinyl or vinylidene halides, e.g. vinyl or vinylidene chloride and bromide; with alkyl vinyl pyridine, e.g. N-vinyl-4- methyl pyridine; with vinyl imidazoles; with (mono)- dialkylaminoalkyl acrylates and methacrylates. e.g. dimethylaminoethyl (meth)-acrylate and their quaternised derivatives; with vinyl and (mcth)-allyl sulphonic acids; and with vinyl and (meth)-allyl phosphonic acids or their esters. All of these copolymers should contain at least 60 72. by weight, of acrylonitrile in a copolymerised form.

The polyether polyurethane compounds of the above general formula may be prepared by known processes as follows:

Bisphenols or five-. six' or seven-membered heterocyclic rings. containing at least two NH-groups. are polyethoxylated, preferably as solvent-free melts, but, if desired, as solutions in an inert solvent and, if necessary. also under pressure in an autoclave in the presence of a catalytic quantity of a strong base, e.g. sodium or potassium hydroxide or sodium or potassium mcthanolate. The degree of ethoxylation may be varied as desired. After determination of their QH-number or molecular weight. the resulting polyether diols, containing aromatic or hcterocyclic structures, are reacted in a stoichiometric excess. with a diisocyanate. This reaction may be carried out in the presence of an inert solvent. (for example. dimethylformamide), but preferably it is carried out without solvent, at temperatures of from to l50C. preferably from 80 to 130C. The reaction is accompanied by the formation of urethane groups. The resulting polyether polyurethane precondensates. containing hydroxyl end groups, are then reacted with a monoisocyanate in a molar ratio of l 2. again preferably without solvent, at temperatures of up to 150C, preferably after first determining the OH-number. The reaction time is from 1 to 6 hours.

The chain length of the pre-condensates and hence also of the polyether polyurethanes depends mainly on two factors:

a. the molecular weight of the polyether diol used.

containing aromatic or heterocyclic groups, and

b. the molar ratio in which the polyether diols and diisocyanatcs are reacted.

The polyether polyurethane compounds vary from waxy to solid substances which are invariably soluble in dimethylformamide. in some cases mild heating is necessary.

Any conceivable bisphenols may, in principle, be used in the preparation of the polyether polyurethanes of the present invention. but it is preferred to use those bisphenols which have a melting point below approximately 170C. This is because they may be ethoxylated as solvent-free melts, for example 2,2-bis-(4hydroxyphenyl )-propane, (bisphenol A. Mp.: from 153 to [56C). Bisphenols which have a higher melting point may be dissolved or suspended in an inert solvent. (for example, dioxane, tetrahydrofuran or dimethylformamide). and. if necessary. ethoxylated under pressure. The following bisphenols are mentioned as examples: hydroquinone, resorcinol, 4-chlororesorcinol, pyrocatechol. l,5-dihydroxy naphthalene. l,6dihydroxy napthalene. l,7-dihydroxy napthalene. 2,6-dehydroxy napthalene. 2,7-dihydroxy naphthalene. bis-(4-hydroxyphenyl )sulphone, 4,4'-dihydroxy-biphenyl, l.l-bis-(4- hydroxyphenyl )-ethane, 2,2-bis-( 4-hydroxyphenyl propane, 2,2-bis-( 3 ,5-dichloro-4-hydroxyphenyl propane, l, l -bis-(4-hydroxyphenyl )-cyclohexane and bis-( 2-hydr0xyl -naphthyl)-methane.

The heterocyclic compounds used in the preparation of the compounds of the present invention may be any compounds with five-. sixor seven-membered heterocyclic rings which contain at least two NH-groups, e.g. piperazine. 2,5-dimethyl piperazine and imidazolidines. It is preferred to use those heterocyclic compounds in which at least one, but preferably both NH-groups are adjacent to carbonyl groups, for example imidazolidone-2-. diketopiperazine. 3.6-dioxol,2,3.o-tetrahydropipcrazine. hydantoins, uracils, quinazoline-2,4-diones or tetrahydroquinazolones-(4).

Ethoxylation of these heterocyclic compounds is preferably carried out in a solvent-free system, provided that the melting point of the compounds is below approximately [C. Compounds with higher melting points may be dissolved or suspended in an inert solvent, (eg. tetrahydrofuran, dioxane or dimethylformamide) and. if necessary, ethoxylated under pressure.

There are in principle no limits to the degree of ethoxylation of the polyether diols, containing aromatic or heterocyclic groups, but, for the purposes of the present invention, polyether diols with molecular weights of from 500 to 3000 are preferred.

Particularly suitable diisocyanates for preparing the polyether polyurethanes of the present invention include cyclohexane-l ,4-diisocyanate. lisocyanatomethyl-S-isocyanatol ,3,3-trimethylcyclohexane, phenylene-l,3diisocyanate, phenylenel.4-diisocyanate. tolylene-2,4-diisocyanate, tolylene- 2,5-diisocyanate, naphthylenel .S-diisocyanate, diphenylmethane-4,4'-diisocyanate, 2,2-bis-(4- isocyanatophenyl)-propane and mixtures thereof. Numerous other diisocyanates are also suitable.

Any monoisocyanates are suitable. in principle, but long-chain aliphatic and cycloaliphatic isocyanates which contain from o to l8 carbon atoms, e. g. stearyl isocyanates and cyclohexyl isocyanate, have been found to be particularly suitable, and it is also advantageous to use aromatic isocyanates, e.g. phenyl or naphthyl isocyanate.

The polyether polyurethanes of the present invention may be added to the spinning solution of the acrylonitrile polymer, either in the solid form or as solutions in dimethylformamide. in quantities of from 0.5 to 15 70, by weight, preferably from 2 to 10 70, by weight, based on the polymer mixture. If the synthesis of the additives is carried out e.g. in dimethylformamide, the required quantity of this solution of additives may be added directly to the spinning solution.

The surface resistance of the shaped structures of the present invention. in particular fibres as indicated in the Examples, was determined using a commercial high-resistance ohmcter, between two electrode plates l cm apart at a measuring voltage of [00 V, according to the proposed standard test DIN 54 345. Before each determination, the fibres were first conditioned for 72 hours in a standard atmosphere of S0 relative humidity at 23C. Under these conditions. the fibres produced according to the invention have an electrical surface resistance of from 5 X 10 to 10 (1.

The fibres according to the invention may be dyed with the conventional dyes without any detrimental effect on the excellent anti-electrostatic character. These fibres are particularly advantageous in cases where subsequent antistatic treatment would otherwise be necessary, for example in curtain material. When employed in this manner. the material is not found to attract any dust due to static electricity produced by friction nor acidic additive, the fibres could be dyed with a basic are there any sticky dressings to hold the dust. dye, Colour Index No. 1 1,085, by the conventional The following Examples are. to further illustrate the methods used for acrylic fibres. When the surface resisinvention without limiting it. tance was then again determined, it was found to be 6 5 X G. This shows that dyeing does not reduce the EXAMPLE antistatic action. Even after repeated washing, the sur- Preparation and antistatic action of th p ly r face resistance of the dyed fibres was still found to be polyurethane which has the following average formula: 6 x 10 Q r C".H3,NHCO(OCH,CH2) 0Q. o cH,cH.,o) COHN C H I C H 3 i' NHCO-(OCH2-CH2] 0Q. c Q. O(CH,CH2O) .,,,coHN C.,.Hm

I C H 3 28.5 parts, by weight, 4,4- EXAMPLE 2 diisocyanatodiphenylmethane were added portionwise Preparation and antistatic action of I... OH

at approximately 100C to 131 parts, by. weight, a 11.7 parts, by weight, 4,4" polyethoxylated bisphenol A which had an average modiisocyanatodiphenylmethane were added dropwise at lecular weight (MW) of 1920. After 3 hours stirring at a temperature of from to C to 134.5 parts, by a temperature of from [00 to 130C, 202 parts, by weight, of the polycthoxylated bisphenol A, ME weight, stearyl isoeyanate were added dropwise. The 1920. After 4 hours stirring at from to C,

mixture was again stirred at 130C and lastly a 25 50- [3.8 parts, by weight. stearyl isoeyanate were added lution was prepared by the addition Of 480 part y dropwise and the mixture was then stirred for 4 hours weight, dimethylformamide. The solution of the resultat 130C thg polycther Polyurethane was used, mgether with an The above polycther polyurethane and the acryloni acrylonit ile cop lym to p p an approximately trile copolymer, described in Example 1, were used to 29 dimcthytfurmamtdc Solution containing prepare a 29 dimcthylformamide solution which y Weight of the copotymcr and y Wetghtof contained 90 70, by weight, of the acrylonitrile copolythe polycther potyurcthahe- (The acrylonitrile P Y" mer and 1O by weight, ofthe polycther polyurethane. Used in this as as in at] the following exam" is Filaments spun from this solution were found to have P was Copolymet of 93 acrylonitrile, 6 methyl a good surface conductivity sufficient for practical puractytats and approximately I methattyt sutphohate poses. Surface resistance: 9 X 10 9; after 10 washings:

with a K-value of 81 (according to Fikentscherl). This 2 X ow Q solution had a viscosity of approximately 240 poise (85C) and was spun into threads by the dry-spinning EXAMPLE 3 p Titre of the fibres dtex- The fibres had a 60 A dimethylformamide solution of the acrylonitrile tensile strength Of 3.2 g/dtex at 12 elongation. The copglymer, as described in Example 1 containing 7 7o, anti-electrostatic action of the additive was determined by weight, based on the total solids content, of the polyby measuring the surface resistance of the fibres at ether polyurethane, as described in Example 2, was

2 C and 5 r i umi ity 11 dfiscl'ibed 65 span to threads. Titre: 3.3 dtex, tensile strength: 3.5

Fresh (unbleached Whitey 3 X Sample after 10 g/dtex at 15 elongation. The following results were washings: 5 X 10" obtained from determinations of the surface resistance:

Since the acrylonitrile copolymer used contained an 3 X 10' (2: after 10 washings; 8 X 10 Q.

EXAMPLE 4 Preparation and antistatic action of the polyether polyurethane having the following average formula:

Cli

13.1 parts, by weight. 4,4 diisocyanatodiphenylmethane were added. at approxi mately 100C, to a solution of 1 16 parts. by weight. of a polyethoxylated bisphenol A, average molecular weight 1 100 in 480 parts, by weight, DMF. The reaction mixture was then stirred for 6 hours at from 126 to l 30C. 30.9 parts. by weight, stearyl isocyanate were then introduced dropwise and the reaction mixture was stirred for 8 hours at 130C.

Fibres spun from an approximately 29 70 solution of a mixture of 90 71 by weight, of the acrylonitrile co polymer from Example 1 and 10 by weight, of the above-mentioned polyether polyurethane had a satis- 0-(CH CH OZ worm-0 a 35.5 parts, by weight. stearyl isocyanate were added to 122.5 parts, by weight, of the polyethoxylated bisphe no! A. average molecular weight 1920. and this reaction mixture was then stirred for 4 hours at from 120 to 130C. Fibres spun from an approximately 25 solution of a mixture of 90 parts, by weight, ofthe acrylonitrile copolymer from Example 1 and 10 by weight, of the compound described above had good antistatic characteristics. Surface resistance: 8 X 10 (1 (fresh fibres); after 10 washings: l X 10"0. After these fibres had been dyed with a basic dye (CI. 1 l 085), they were found to have a surface resistance of 3 X 100 which was not altered by further washings.

EXAMPLE 6 Preparation and antistatic action of a polyether polyfactory surface conductivity. Surface resistance of urethane of the following average formula:

CH CH fresh fibres: 5 X 10" .0; after [0 washings: 1 X 10" Q. 7.7 parts, by weight, l-isocyanatomethyl-3-isocyanato- EXAMPLE 5 Preparation and antistatic action of 3.5.5-trimethyl cyclohexane were slowly added, at from to C, to 132 parts, by weight. of the ethoxylated bisphenol A, average molecular weight of 1920. The mixture was then stirred for 4 hours at from H f 3 0 :1 -n noc- 0Ct1 Ch -QGTGO-L ca ca oL ZO-COHN-C n 120 to I30C. 20.4 parts, by weight, stearyl isocyanate were then added dropwise and the mixture was stirred for a further 4 hours at 130C. Fibres spun from an approximately 29 7: solution of a mixture of 90 by EXAMPLE 12 Preparation and antistatic action of a polyether polyurethane having the following general formula:

weight, of the acrylonitrile copolymer described in Example l and 10 by weight, of the above compound had a good surface conductivity. Surface resistance: Fresh fibres 1 X 10" (1; after 10 washings: 4 X 10" .0.

EXAMPLE 7 A 29 DMF solution was prepared from the polyether polyurethane described in Example 6. The solution contained 94 by weight, of the acrylonitrile copolymer described in Example 1 and 6 by weight, of the polyether polyurethane. Filaments spun from this solution had a surface resistance of 4 X 10'" (fresh fibres) and 9 X 10" 9 (after l0 washings).

l 1.8 parts, by weight, 4,4- diisocyanatodiphenylmethane were added at approximately l0OC, to a solution of I36 parts, by weight, polyethoxylated l,S-dihydroxy-naphthalene, average molecular weight of I480 in 480 parts, by weight, DMF. After stirring for several hours, 12.3 parts, by weight, m-tolyl isocyanate were added. The reaction mixture was then stirred for 6 hours at 130C.

Fibres spun from an approximately 29 solution of a mixture of 7r. by weight, of acrylonitrile copolymer from Example I and l() /r, by weight, of the polyether polyurethane described above had a good surface conductivity. Surface resistance: Fresh fibres 2 X 10" (I; after l0 washings 8 X IO" (1.

EXAMPLE l3 Preparation and antistatic action of a polyether polyurethane having the following general formula:

CH O O l 1 i CH (JC .c

l c: l1 NHG0- -(OCl-l CH -N\ /N-(Cl'l C!-l 0) -oo141-|-cn micom-(ocu ca .i1\

C C I I O 0 (011 611 0) -couu-c n Quantity of additive Surface resistance in in 7% by fresh after 3 after dyeing Examples in n weight sample washings and 3 washings 8 2 15 10.0 I X l0" 3 X 10'" 5 X l0 9 2 15 7.5 3 X10" 8 X 10'" 2 X l0'" l0 2 8 10.0 4 X10 5 X 10" 9 X [0 ll 4 8 10.0 6 X 10 2 X I0 I X 10'" o (CH2CH2O)-20-COHN-C 28.6 parts, by weight, 4,4- diisocyanatodiphenylmethane were added portionwise to 131.3 parts. by weight, of a quinazoline-2.4-dione polyethoxylated in the land 3-positions and average molecular weight of 1920. Following this addition, the b reaction mixture was stirred for 5 hours at 130C and 20.2 parts by weight. stearyl isocyanate were then added dropwise. The reaction mixture was then stirred for 5 hours at 130C. Threads of acrylontrile copolymer containing approximately 10 90, by weight, ofthis 3 antistatic agent have the following surface resistance: Fresh threads 9 X 10 (I; after 10 washings: 6 X 10' .(2.

EXAMPLE 14 Preparation and antistatic action ofa polyether poly 35 urethane having the following general formula:

ether polyurethane compound of the general formula in which A denotes a bivalent radical of an aromatic biphenol of the formula O-R"O in which R" denotes a bivalent aromatic radical consisting of one or more condensed aromatic rings or of aromatic rings which are joined together by a single bond or by a bridge member selected from the c m yd 011 :21 0) moiwO 1 1.9 parts, by weight. diisocyanatodiphenylmethane were added. at approximately 130C. to 136 parts, by weight. of a polyethoxylated diketopiperazine. average molecular weight of 1430. The mixture was then stirred for several hours at 130C and l 1.9 parts by weight, cyclohexyl isocyanate were then added. The mixture was then stirred for a further 5 hours at approximately 130C. Acrylonitrile copolymer threads which contained approximately 10 k. by weight. of the polyether polyurethane described above had the following surface resistances: Fresh threads 1 X 10'" (I; after 10 washings: 9 X 10' Q.

We claim:

1. A shaped structure of an acrylonitrile polymer containing at least 60% by wieght acrylonitrile and containing as an antistatic additive from 0.5 to 15 Yr, by weight, based on the total mixture. of at least one polyit denotes a bivalent five-. sixor seven-membered heterocyclic radical which contains at least two nitrogen atoms and which is linked in the polycther chain by two nitrogen atoms:

R denotes a C C alkyl, cycloalkyl, aralkyl or alkaryl radical. any of which radical may be substituted by halogen or alkyl;

R denotes an alkylene, cycloalkylene. arylene, aralkylene or alkarylene radical, any of which radicals may be substituted by halogen or alkyl;

n denotes an integer of from 5 to S0; and

p denotes O or an integer of from I to ID. 2. The shaped structure of claim I, wherein in the 2 general formula the bivalent radical R is CH 2 4. The shaped structure of claim I. wherein in the general formula the bivalent radical R is CH ca l0 3. The shaped structure of claim 1, wherein in the general formula the bivalent radical R is 

1. A SHAPED STRUCTURE OF AN ACRYLONITRITE POLYMER CONTAINING AT LEAST 60% BY WEIGHT ACRYLONITRITE AND CONTAINING AS AS ANTISTASTIC ADDITIVE FROM 0.5 TO 15%, BY WEIGHT, BASED ON THE TOTAL MIXTURE, OF AT LEAST ONE POLYETHER POLYURETHANE ETHER COMPOUND OF THE GENERAL FORMULA
 2. The shaped structure of claim 1, wherein in the general formula the bivalent radical R'' is
 3. The shaped structure of claim 1, wherein in the general formula the bivalent radical R'' is
 4. The shaped structure of claim 1, wherein in the general formula the bivalent radical R'' is 